Summary: | 碩士 === 弘光科技大學 === 環境工程研究所 === 96 === The characteristics of wastewater from textile and dyeing industries are often with high color intensity, high chemical oxidation demand, and refractory to traditional treatment processes. Thus, the effluents from dyeing industries are not be able to fulfill the effluent standards in most cases. To promote the wastewater treatment efficiency and save operation time, we propose a process using manganese dioxide and ozone to remove color and mineralize the dye wastewater. The parametric study of using manganese dioxide alone process to dealing with azo dyes, Acid Black 24 and Acid Blue 113, were performed to obtain optimal reaction time, manganese dioxide dosage, initial dye concentration, and pH. Then, manganese dioxide combined with ozone process was tested with the optimal operating conditions. In this work, the dye removal efficiencies for two azo dyes, AB24 and AB113, in concentration of 100 mg/L and addition of 40 g/L manganese dioxide were both over 80%, TOC were over 55 and 27%. At acidic condition of pH2, the removal efficiencies of dye and TOC were over 95 and 40%, respectively for both AB24 and AB113. The results presented that the manganese dioxide was powerful for treat dye, color and TOC. In the FTIR spectrum, the peaks of -N=N- double bond was eliminated after the manganese dioxide reaction. Ozonation treatment can significantly remove the color caused by dye molecules. Using ozonation alone can reduce about 40% of dye color, but only 5% of TOC. The combination process of manganese dioxide and ozone is proved to be a promising technology for dealing with dye wastewater, which can completely reduce the dye color in shorter reaction time and also destruct the TOC, removal efficiencies of dye over 90% and TOC over 40~50%. The advantages of this combination process are powerful, shorter reaction time and less energy demand.
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